Preheat oven to 400º. In a heavy saucepan, combine preserves and water. Over medium high heat, bring mixture to a boil; reduce heat and simmer for 5 minutes, stirring constantly. Remove mixture from heat adn stir in lemon juice, nutmeg and cinnamon. Arrange sweet potatoes in a baking pan. Using a pastry brush, baste potatoes thoroughly with sauce, using about half the sauce. Bake about 40 minutes, or until tender, basting with remaining sauce about halfway through cooking time.